A pipetting mechanism in a protein blotting instrument

Abstract

The present invention provides a pipetting mechanism in a protein blotting instrument, comprising a pipetting needle, a pipetting arm, and a cam, wherein the pipetting needle is fixed on the pipetting arm, the cam is in contact with the pipetting arm, a first rotating fulcrum is provided on the pipetting arm, the movement of the cam can drive the pipetting needle to rotate around the first rotating fulcrum, the pipetting needle can be used to absorb waste liquid in a reaction tank, and the pipetting mechanism also includes a supporting element, the supporting element is retractable or elastic, and the supporting element can allow the pipetting arm to always maintain contact with the cam. The structural design of the present invention allows the pipetting needle to remain stationary when in contact with the reaction tank, solving the problem of the pipetting needle hitting the needle and damaging the reaction tank in the prior art; the ordinary arc surface and the concentric arc surface on the cam have a smooth transition, so that there will be no excessive impact during the contact between the pipetting needle and the bottom of the reaction tank, protecting the reaction tank and ensuring the installation stability of the pipetting needle.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a liquid transfer mechanism in a protein blotting instrument. Background Art

[0002] Western blotting is a protein separation and detection technique that combines electrophoresis with transfer immunolabeling. Compared to other protein separation techniques, it offers advantages such as high sensitivity, ease of use, high specificity, and the ability to perform both qualitative and semi-quantitative analysis. It has been successfully applied in a variety of fields, including protein characterization. Currently, Western blotting-related testing procedures are typically performed on automated Western blotting instruments.

[0003] The automatic protein blotting instrument can complete the entire process of automatic liquid preparation, liquid aspiration, incubation, flushing, and substrate addition by adding test specimens according to experimental requirements using the set operating procedures. It has the advantages of providing safety for operators and reducing human operation errors. It is more reliable, has more standardized operation, and saves time and effort.

[0004] The technical problem to be solved by the present invention is that during the waste liquid aspiration process of an automatic protein blotting instrument, the aspiration needle cannot effectively fit into the reaction tank to aspirate the liquid, thereby causing differences in experimental results. To address this problem, a protein blotting instrument pipetting mechanism is provided. The device can effectively enable the pipetting mechanism to cleanly aspirate waste liquid within a certain range, greatly reducing the problem of inaccurate detection caused by the aspiration problem. Summary of the Invention

[0005] The object of the present invention is to provide a pipetting mechanism in a protein blotting instrument to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is a pipetting mechanism in a protein blotting instrument, comprising a pipetting needle, a pipetting arm, and a cam, wherein the pipetting needle is fixed on the pipetting arm, the cam is in contact with the pipetting arm, and a first rotating fulcrum is provided on the pipetting arm. The movement of the cam can drive the pipetting needle to rotate around the first rotating fulcrum, and the pipetting needle can be used to absorb waste liquid in the reaction tank.

[0007] Furthermore, it also includes a supporting element, which is retractable or elastic, and can enable the pipetting arm to always maintain contact with the cam.

[0008] Furthermore, the supporting element is a spring, and the spring is always in a stretched or compressed state.

[0009] Furthermore, the cam and the liquid suction arm are arranged on a mounting plate, the liquid suction arm is connected to the mounting plate through the first rotation fulcrum, and a first motor is also installed on the mounting plate. The output shaft of the first motor is connected to the cam, and the first motor can drive the cam to rotate. The output shaft of the first motor is the rotation center of the cam.

[0010] Furthermore, the cam has a flange surface, and a concentric arc surface is provided on the flange surface, and the center point of the concentric arc surface coincides with the rotation center of the cam.

[0011] Furthermore, the point on the flange surface located on the concentric arc surface is at the shortest distance from the rotation center of the cam. When the concentric arc surface contacts the pipetting arm, the pipetting needle is at the lowest position and just contacts the bottom of the reaction tank.

[0012] Furthermore, the cam is also provided with a common arc surface, and the distances between two adjacent points on the common arc surface and the rotation center point of the cam are not equal. When the common arc surface contacts the pipetting arm, as the first motor drives the cam to rotate, the pipetting needle will move.

[0013] Furthermore, the connection portion between the common arc surface and the concentric arc surface transitions smoothly.

[0014] Furthermore, the reaction tank is provided on the detection plate, and the detection plate is provided with a plurality of reaction tanks, and the reaction tanks are arranged side by side;

[0015] The pipetting mechanism further comprises a moving device, which can drive the pipetting needle to move, so that the pipetting needle can draw waste liquid into the designated reaction tank.

[0016] Furthermore, the moving device includes a synchronous belt mechanism, which is driven by a second motor, the cam and the liquid suction arm are provided on a mounting plate, the mounting plate is connected to the first frame, the moving device also includes a second frame, the second frame is slidably connected to the first frame, and the first frame is connected to the conveyor belt of the synchronous belt mechanism through a connecting device;

[0017] The mobile device further includes a positioning sensor, which is mounted on the second frame and is used to monitor the real-time position of the first frame, thereby indirectly reflecting the real-time positions of the liquid discharge tube and the liquid aspiration needle.

[0018] The second frame is provided with a protrusion, and the protrusion can limit the position of the first frame;

[0019] When the liquid-pipetting needle extracts the waste liquid in the reaction tank, the reaction tank is in a horizontal position or tilted toward the position of the liquid-pipetting needle.

[0020] In summary, the beneficial effects of the present invention are:

[0021] (1) The structural design of the present invention allows the pipette needle to remain stationary when in contact with the reaction tank, thereby solving the problem in the prior art of the pipette needle hitting the needle and damaging the reaction tank.

[0022] (2) The smooth transition between the ordinary arc surface and the concentric arc surface on the cam of the present invention prevents excessive impact when the pipette needle contacts the bottom of the reaction tank, thereby protecting the reaction tank and ensuring the installation stability of the pipette needle.

[0023] (3) The present invention does not require frequent speed control of the first motor through the control circuit, eliminating the potential risk of the aspiration needle colliding with the bottom of the reaction tank; in addition, using the device of the present invention, the control circuit does not strictly control the rotation angle of the first motor, solving the problem of the inability to drain the waste liquid due to errors in the prior art.

[0024] (4) The present invention is provided with a waste liquid overflow alarm device to provide an overflow alarm when the waste liquid in the waste liquid bottle reaches a certain volume.

[0025] (5) The discharge pipe and the pipette needle of the present invention are separated and do not interfere with each other. The discharge pipe is used to add new reagents into the reaction tank, while the pipette needle is only used to remove the tested reagents from the reaction tank, so that they will not contaminate each other. Therefore, when the function of the pipetting structure is switched, cleaning is no longer required, and it is easy to use.

[0026] (6) In the present invention, bubble sensors are provided between the waste liquid pump and the waste liquid bottle, and between the quantitative syringe and the reagent storage bottle. The bubble sensor between the quantitative syringe and the reagent storage bottle can be used to monitor whether there are bubbles in the quantitative syringe, and can reflect whether the reagent added to the reaction tank by the quantitative syringe is insufficient; and the bubble sensor between the waste liquid pump and the waste liquid bottle can be used to monitor whether the waste liquid has been extracted. The setting of the connection between the sensor and the control circuit can feedback the current status of the pipeline, thereby improving the reliability of the pipetting mechanism.

[0027] (7) When the aspiration needle in the pipetting mechanism draws out the waste liquid in the reaction tank, the control circuit can control the reaction tank to a horizontal position or the control circuit can control the reaction tank to be slightly tilted toward the position of the aspiration needle. The slightly tilted state can allow the waste liquid to flow under the action of gravity, which helps the aspiration needle to drain the waste liquid in the reaction tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 This is a schematic diagram of the structure of a pipetting mechanism in one direction in a protein blot instrument of the present invention;

[0030] Figure 2 This is a schematic structural diagram of a pipetting mechanism in a protein blot instrument of the present invention in another direction;

[0031] Figure 3 is an output speed curve diagram given to the first motor in the motion simulation;

[0032] Figure 4 This is the speed curve obtained from the first rotation fulcrum in the motion simulation;

[0033] Figure 5 This is a schematic diagram of the contact between the concentric arc surface on the cam and the liquid suction arm in the motion simulation;

[0034] Figure 6 Schematic diagram of the internal liquid path structure of an automatic protein blotting instrument in one embodiment of the present invention;

[0035] Figure 7 It is a schematic diagram of the structure of the reaction tank on the detection plate;

[0036] Figure 8 yes Figure 7 Schematic diagram of the enlarged structure of the middle reaction tank. DETAILED DESCRIPTION

[0037] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the embodiments of the present invention are further described in detail below with reference to the accompanying drawings. It should be pointed out that the embodiments are only detailed explanations of the present invention and should not be regarded as limitations of the present invention. All features disclosed in the embodiments of the present invention, or all steps in the methods or processes disclosed, except for mutually exclusive features and / or steps, can be combined in any way.

[0038] In order to enable technical personnel to better understand the technical solution of the present invention, the working method of the protein blotting instrument is first briefly described: protein blotting-related tests are usually performed on an automatic protein blotting instrument. The automatic protein blotting instrument is provided with a detection plate 52, and the detection plate 52 is provided with a reaction tank 53 for placing a membrane 54 (the membrane is usually fixed on a membrane strip) and adding reagents. The reagent needs to submerge the membrane and swing back and forth through the rocking mechanism of the instrument itself to allow the membrane and antigen to fully fuse and react, thereby obtaining accurate test results.

[0039] After the detection is completed, the pipetting mechanism in the protein blotting instrument needs to draw out the reagents in the reaction tank 53. The pipetting mechanism includes a pipette needle (or a tube). In order to allow the pipette mechanism to drain the reagents in the reaction tank as completely as possible, the pipette needle in the pipette mechanism needs to contact the bottom of the reaction tank. The technical problem in the existing technology is that it is very difficult to accurately control the position of the pipette needle, resulting in the automatic protein blotting instrument being unable to effectively fit the pipette needle with the bottom of the reaction tank to absorb the liquid during the waste liquid aspiration process, resulting in incomplete absorption of the liquid in the reaction tank, which may cause differences in the experimental results and greatly reduce the problem of inaccurate detection caused by the aspiration problem.

[0040] The present invention provides a pipetting mechanism in a protein blotting instrument for completely draining the waste liquid in the reaction tank 53, comprising a pipetting needle 101, the pipetting needle 101 being fixed to a pipetting arm 104, the pipetting arm 104 being provided with a first rotation fulcrum 102, the pipetting needle 101 being capable of rotating around the first rotation fulcrum 102, the pipetting mechanism further comprising a cam 103, the cam 103 being in contact with the pipetting arm 104 to form a cam mechanism. Specifically, the cam mechanism further comprises a supporting element 105, which may be retractable or elastic, and whose function is to allow one end face of the pipetting arm 104 to always remain in contact with the flange surface of the cam 103. When the cam 103 begins to rotate, the pipetting arm 104 can swing around the first rotation fulcrum 102 according to the flange surface of the cam 103. By changing the shape of the flange surface of the cam 103, the movement speed, movement direction or stagnation time of the pipetting needle 101 can be controlled.

[0041] Preferably, in this embodiment, the supporting element 105 is a spring, one end of which is connected to the first frame 106 and the other end of which is connected to the pipetting arm 104, so that one end surface of the pipetting arm 104 is always in contact with the flange surface of the cam 103, forming a cam mechanism. In this embodiment, with the first rotation fulcrum 102 on the pipetting needle 101 as the dividing center, the pipetting needle 101 and the cam 103 are connected to both sides of the pipetting arm 104, with reference to the attached Figure 2, the pipetting needle 101 is fixed to the left end of the pipetting arm 104, and the right end of the pipetting arm 104 is in contact with the cam 103. In this state, in order to make the pipetting arm 104 contact with the cam 103, when the spring is connected to the left end of the pipetting arm 104, as long as the pipetting arm 104 is within the working swing range, the spring is always in a stretched state; in some other embodiments, when the spring is connected to the right end of the pipetting arm 104, as long as the pipetting arm 104 is within the working swing range, the spring is always in a compressed state. In addition, in some other embodiments, the pipette needle 101 and the cam 103 are connected to the same side of the pipette arm 104, for example, from left to right they are: the pipette needle 101, the cam 103, and the first rotation fulcrum 102. In this state, the spring should also be connected to the pipette arm 104 at the left side of the first rotation fulcrum 102, and the spring is always in a stretched state when the pipette arm 104 is within the working swing range.

[0042] Preferably, in this embodiment, the cam 103 and the pipetting arm 104 are both arranged on a mounting plate 107, and the pipetting arm 104 is connected to the mounting plate 107 through the first rotating fulcrum 102 thereon. A first motor 108 is also installed on the mounting plate 107, and the output shaft of the first motor 108 is connected to the cam 103, which can drive the cam 103 to rotate. The mounting plate 107 is connected to the first frame 106, and the spring is always in a stretched state. The tension generated by the spring makes the pipetting arm 104 fit with the cam 103, so that in the process of the first motor 108 driving the cam 103, it is ensured that the contact between the pipetting needle 101 and the reaction tank 53 will not have too much impact. The corresponding cam 103 can be designed according to the size parameters of the reaction tank 53 to ensure that the pipetting port of the pipetting needle 101 can be located at the bottom of the reaction tank 53 when extracting waste liquid.

[0043] Preferably, the cam 103 has a concentric arc surface 109, and the center point of the arc of the concentric arc surface 109 coincides with the rotation center point of the cam 103 (the output shaft of the first motor 108). That is, as the first motor 108 drives the concentric arc surface 109 on the cam 103 to start contacting the pipetting arm 104, since the distance between each point on the concentric arc surface 109 and the rotation center of the cam 103 is the same, then in the next short period of time, the pipetting arm 104 will not move due to the movement of the cam 103, that is, during this short period of time, the pipetting needle 101 on the pipetting arm 104 will remain stationary. Furthermore, the point where the cam 103 is located on the concentric arc surface 109 is at the shortest distance from the rotation center of the cam 103. When the concentric arc surface 109 on the cam 103 contacts the pipetting arm 104, the pipetting needle 101 is at the lowest position and just contacts the bottom of the reaction tank 53. Figure 5 As shown, since in this position, the aspiration needle 101 will remain stationary, that is, the speed is zero, which can avoid the aspiration needle 101 from hitting the bottom of the reaction tank 53, and the pipetting mechanism in the prior art is generally difficult to complete the buffering control of the aspiration needle, and there is a risk of damaging the reaction tank or hitting the needle. In this example, the cam 103 is also provided with a common cambered surface 110. Generally, the distance between the two adjacent points on the common cambered surface 110 and the rotation center point of the cam 103 is not equal. When the common cambered surface 110 contacts the aspiration arm 104, as the first motor 108 drives the cam 103 to rotate, the aspiration needle 101 will move, and the common cambered surface 110 and the concentric cambered surface 109 connecting portion have a smooth transition, which makes it possible for the aspiration needle 101 to not have excessive impact during the contact process with the bottom of the reaction tank 53, protecting the reaction tank 53 (generally made of plastic) and ensuring the installation stability of the aspiration needle 101.

[0044] Preferably, the first motor 108 is connected to a control circuit, and the control circuit mainly controls the start and stop of the first motor 108. The motor in a traditional protein blotting instrument is also connected to the control circuit, and the motor is directly connected to the aspiration needle through the aspiration arm, and the control circuit in the traditional protein blotting instrument needs to control multiple parameters: speed, start and stop, and rotation angle. Any slight change in any of these parameters will have a great impact on the aspiration needle 101: for example, when the aspiration needle 101 moves to the lowest position, if the control circuit does not control the speed of the first motor 108 to drop to zero or the control circuit does not shut down the first motor 108 in time to make its speed drop to zero, then the first motor 108 will have a speed limit. It is easy to drive the pipette needle 101 to collide with the bottom of the reaction tank 53; for example, if the control circuit controls the first motor 108 to have a rotation angle deviation, assuming that the first motor 108 controls the pipette needle 101 to rotate twenty degrees, the pipette needle 101 just contacts the bottom of the reaction tank 53. If the control circuit fails at this time, causing the first motor 108 to rotate twenty-one degrees, then the pipette needle 101 is no longer in contact with the bottom of the reaction tank 53, which will cause the pipette needle 101 to be unable to drain the reagent in the reaction tank 53. In the present invention, as long as the concentric arc surface 109 on the cam 103 contacts the pipette arm 104, no matter how much the speed of the first motor 108 is at this time, the pipette needle 101 on the pipette arm 104 can remain stationary, that is, the speed is zero, so there is no need to frequently control the speed of the first motor 108 through the control circuit, eliminating the potential risk of the pipette needle 101 and the bottom of the reaction tank 53. In addition, by utilizing the technical solution of the present invention, the control circuit is not so critical in controlling the rotation angle of the first motor 108, because when the concentric arc surface 109 on the cam 103 contacts the pipetting arm 104, the pipetting needle 101 is in contact with the bottom of the reaction tank 53 and remains stationary. Even if the control circuit fails, the first motor 108 rotates one degree, two degrees more... one degree, two degrees less... As long as the concentric arc surface 109 and the pipetting arm 104 remain in contact, it will not affect the pipetting needle 101 from draining the reagent in the reaction tank 53, thereby solving the problem in the prior art that the reagent cannot be drained due to errors.

[0045] In order to better enable technical personnel to understand the technical solution of the present invention and reflect the technical effects that can be achieved by the present invention, refer to the attached Figure 3 -Attached Figure 5 The cam 103 and the liquid suction arm 104 are subjected to a simple motion simulation in principle, and the first motor 108 is given an angular velocity of 15 r / min (see the attached figure). Figure 3201 in the figure), that is, the angular velocity of the cam 103 is also 15 r / min, and the angular velocity curve of the first rotating fulcrum 102 on the pipetting arm 104 is obtained (as shown in the attached figure). Figure 4 As shown in Table 202 in FIG, according to the formula v=w×r, the angular velocity curve of the first rotating fulcrum 102 can indirectly reflect the speed change of the pipetting needle 101 on the pipetting arm 104, and its speed change is proportional to the angular velocity change of the first rotating fulcrum 102. Figure 5 1 is a state diagram of the pipetting arm 104 when the angular velocity of the first rotation fulcrum 102 is zero. It can be seen that the left end of the pipetting arm 104 is in a state of swinging down to the lowest position (the pipetting needle 101 is located on the left end of the pipetting arm 104). At this time, the pipetting needle 101 is in a state of contacting the bottom of the reaction tank 53. Figure 4 It can be clearly seen that the aspiration needle 101 is in contact with the bottom of the reaction tank 53 for a period of time and remains stationary. In the process of the aspiration needle 101 approaching or moving away from the bottom of the reaction tank 53, the movement speed of the aspiration needle 101 gradually decreases and increases, respectively, which can effectively prevent the aspiration needle 101 from colliding with the bottom of the reaction tank 53. The pipetting mechanism in the protein blot instrument provided by the present invention can complete the aspiration operation through mechanical design and circuit control, thereby reducing the risk of a collision and adapting to the deviation of the test results caused by unclean aspiration due to environmental changes.

[0046] Typically, the pipetting mechanism needs to provide a suction force to complete the suction of the waste liquid in the reaction tank 53, and the most common suction force is negative pressure. Figure 6 The pipetting mechanism further includes a pipetting pump 111 connected to the pipetting needle 101. The waste liquid pump 111 provides power for sucking waste liquid. The other end of the waste liquid pump 111 is connected to a waste liquid bottle 112. Negative pressure is established by the waste liquid pump 111, and the pipetting needle 101 begins to suck waste liquid. The pipetting needle 101 sucks waste liquid from the reaction tank 53 and discharges it into the waste liquid bottle 112 through the waste liquid pump 111. The waste liquid pump 111 is controlled by a control circuit so as to complete the pipetting action in the correct reaction tank.

[0047] Preferably, the waste liquid pump is connected to the control circuit, and a waste liquid overflow alarm device 113 is provided at the upper end of the waste liquid bottle 112 so as to provide an overflow alarm when the waste liquid in the waste liquid bottle 112 reaches a certain capacity. The waste liquid overflow device 113 is connected to the control circuit, and when the set capacity is reached, the control circuit provides an alarm and stops the waste liquid suction action.

[0048] In some embodiments, the pipette needle 101 can complete two operations: extracting waste liquid and adding new reagents. Since both the extraction of waste liquid and the addition of new reagents are completed through the pipette needle 101, in order to avoid the waste liquid remaining in the pipette needle 101 from contaminating the newly added reagent, the pipette needle 101 needs to be cleaned during the switching interval between extracting waste liquid and adding new reagents. The cleaning operation can be manual or automatic.

[0049] In this embodiment, the pipetting structure further includes a discharge pipe 114, which is used to add new reagents to the reaction tank 53, while the aspiration needle 101 is only used to draw out the tested reagents from the reaction tank 53. In this way, adding new reagents and drawing out waste liquid are separated by two pipelines and will not contaminate each other. Therefore, when the function of the pipetting structure is switched, no cleaning is required. At the same time, when drawing out waste liquid, the aspiration needle 101 needs to contact the bottom of the reaction tank 53 so that the waste liquid in the reaction tank 53 can be drained. When the discharge pipe 114 adds reagents to the reaction tank 53, the discharge pipe 114 does not need to contact the reaction tank 53, so as to avoid contamination of the discharge pipe 114 by the waste liquid remaining in the reaction tank 53. Furthermore, the liquid discharge tube 114 is connected to a quantitative syringe 115 or a quantitative pump, so that the liquid discharge tube 114 can add a quantitative amount of reagent to the reaction tank 53 to achieve quantitative testing. The quantitative syringe 115 is also connected to a reagent storage bottle 116, which is used to store reagents, and the quantitative syringe 115 can extract reagents from the reagent storage bottle 116. Preferably, the quantitative syringe 115 is connected to a solenoid valve 117, which can switch the pipeline connected to the quantitative syringe 115, thereby switching the connection between the quantitative syringe 115 and the reagent storage bottle 116 and the quantitative syringe 115 and the liquid discharge tube 114.

[0050] Preferably, the discharge pipe 114 is provided with multiple roots, as shown in the attached Figure 2 and attached Figure 6 As shown, these different discharge tubes 114 can be used to add different reagents to the reaction tank 53. Different reagents are added through different discharge tubes 114 to avoid mutual contamination between different reagents. Preferably, these discharge tubes 114 are fixed on a support 118. These discharge tubes 114 are arranged in a straight line to adapt to the shape of the reaction tank 53 (generally long strip shape) to facilitate the addition of reagents. Preferably, the support 118 is fixed on the first frame 106 so that the discharge tube 114 can move with the aspiration needle 101.

[0051] Preferably, sensors are provided between the paths of the waste liquid pump 111 and the waste liquid bottle 112, and between the quantitative syringe 115 and the reagent storage bottle 116. The sensors may be bubble sensors or other sensors commonly used in the art. In the present embodiment, the bubble sensor between the quantitative syringe 115 and the reagent storage bottle 116 can be used to monitor whether there are bubbles in the quantitative syringe 115, and can reflect whether the reagent added to the reaction tank 53 by the quantitative syringe 115 is insufficient. The bubble sensor between the waste liquid pump 111 and the waste liquid bottle 112 can be used to monitor whether the waste liquid has been extracted. These sensors are connected to a control circuit, and the sensors can feedback the status of the current waste liquid pipeline, thereby improving the reliability of the pipetting mechanism.

[0052] Considering that multiple reactions are generally required during detection by an automatic protein blotting instrument, most automatic protein blotting instruments currently on the market have multiple reaction tanks 53, and the reaction tanks 53 are arranged side by side, as shown in the attached figure. Figure 7 , Attachment Figure 8 As shown, the membrane is fixed on a membrane strip 54, and the membrane strip 54 is placed at the bottom of the reaction tank 53. In order to enable the pipetting mechanism to perform detection on the designated reaction tank 53 and to aspirate waste liquid from the designated reaction tank 53 after the detection, the pipetting mechanism in the present invention further includes a moving device, which can drive the discharge tube 114 and the aspiration needle 101 in the pipetting mechanism to move, so that the discharge tube 114 can add reagents to the designated reaction tank 53, and the aspiration needle 101 can aspirate waste liquid from the designated reaction tank 53.

[0053] Preferably, in this embodiment, the moving device includes a synchronous belt mechanism 119, which is driven by a second motor 120. The moving device also includes a second frame 121, which is connected to the first frame 106 in a sliding manner. Specifically, the second frame 121 and the first frame 106 are connected in a sliding manner through the cooperation of sliders and rails 125. In some other embodiments, the first frame 106 can also perform linear motion on the second frame 121 by other means, such as a screw slider, a linear motor, a hydraulic push rod, etc. The first frame 106 is connected to the conveyor belt of the synchronous belt mechanism 119 by a connecting device 122. The connecting device 122 can be a clip. By clamping the conveyor belt of the synchronous belt mechanism 119 in the middle, the first frame 106 is fixed to the synchronous belt mechanism 119. When the second motor 120 drives the synchronous belt mechanism 119 to move, the synchronous belt mechanism 119 drives the first frame 106 to slide on the second frame 121 through the connecting device 122, and the discharge tube 114 and the pipette needle 101 on the first frame 106 will move with the first frame 106. By controlling the number of revolutions and / or angles of the second motor 120, precise movement of the first frame 106 can be achieved, so that the discharge tube 114 and the pipette needle 101 are aligned with the designated reaction tank 53, thereby realizing the reagent addition and waste liquid extraction operations of the designated reaction tank 53.

[0054] Preferably, the mobile device also includes a positioning sensor, which is installed on the second frame 121. There can be multiple positioning sensors for monitoring the real-time position of the first frame 106 on the slider rail 125. The real-time position of the first frame 106 can reflect the real-time position of the discharge tube 114 and the aspiration needle 101.

[0055] Preferably, two upwardly protruding protrusions 126 are respectively provided on the second frame 121 at both ends of the slider rail 125. The protrusions 126 can limit the slider rail 125 to prevent the slider rail 125 from moving excessively and causing the slider to fall off.

[0056] The reaction tank in the automatic protein blotting instrument can be swung at a certain angle so that the reagent can fully react with the membrane strip, and the control circuit can control the reaction tank 53 to swing to a specified position. When the discharge pipe 114 in the pipetting mechanism in the automatic protein blotting instrument needs to add reagent, the control circuit controls the reaction tank 53 to a horizontal position, and the discharge pipe 114 starts to add reagent in the reaction tank 53, and the reaction tank 53 in a horizontal state is not easy to overflow reagent; When the pipetting needle 101 in the pipetting mechanism in the automatic protein blotting instrument needs to extract the waste liquid in the reaction tank 53, the control circuit controls the reaction tank 53 to a horizontal position or the control circuit controls the reaction tank 53 to tilt slightly to the position of the pipetting needle 101. It should be noted that the waste liquid in the reaction tank 53 can not be caused to leak out under a slightly tilted state. The slightly tilted state can make waste liquid flow under the action of gravity, which helps the pipetting needle 101 to drain the waste liquid in the reaction tank 53.

[0057] The above is only a specific implementation method of the invention, but the scope of protection of the invention is not limited to this. Any changes or substitutions that are not conceived through creative work should be included in the scope of protection of the invention. Therefore, the scope of protection of the invention should be based on the scope of protection defined in the claims.

Claims

1. A pipetting mechanism in a protein blotting instrument, characterized in that: The device comprises a pipette needle, a pipette arm, and a cam, wherein the pipette needle is fixed on the pipette arm, the cam contacts the pipette arm, a first rotation fulcrum is provided on the pipette arm, and the movement of the cam can drive the pipette needle to rotate around the first rotation fulcrum, and the pipette needle can be used to absorb waste liquid in the reaction tank; The pipetting mechanism further includes a supporting element, which is retractable or elastic and allows the pipetting arm to always maintain contact with the cam; The cam and the liquid suction arm are arranged on a mounting plate, the liquid suction arm is connected to the mounting plate via the first rotation fulcrum, and a first motor is also mounted on the mounting plate; the mounting plate is connected to the first frame; The cam has a flange surface, and a concentric arc surface is provided on the flange surface, and the center point of the concentric arc surface coincides with the rotation center of the cam; The cam is further provided with a common arc surface, and the distances between two adjacent points on the common arc surface and the rotation center point of the cam are not equal. When the common arc surface contacts the pipetting arm, as the first motor drives the cam to rotate, the pipetting needle moves; The connection portion between the common arc surface and the concentric arc surface has a smooth transition; One end of the supporting element is connected to the first frame, and the other end is connected to the liquid suction arm, so that one end surface of the liquid suction arm is always in contact with the flange surface of the cam to form a cam mechanism.

2. The liquid transfer mechanism in a protein blotting instrument according to claim 1, characterized in that: The supporting element is a spring, and the spring is always in a stretched or compressed state.

3. The liquid transfer mechanism in a protein blotting instrument according to claim 1, characterized in that: The output shaft of the first motor is connected to the cam. The first motor can drive the cam to rotate. The output shaft of the first motor is the rotation center of the cam.

4. The liquid transfer mechanism in a protein blotting instrument according to claim 1, characterized in that: The point on the flange surface located on the concentric arc surface is at the shortest distance from the rotation center of the cam. When the concentric arc surface contacts the pipetting arm, the pipetting needle is at the lowest position and just contacts the bottom of the reaction tank.

5. The liquid transfer mechanism in a protein blotting instrument according to claim 1, characterized in that: The reaction tank is arranged on the detection plate, and the detection plate is provided with a plurality of reaction tanks, and the reaction tanks are arranged side by side; The pipetting mechanism further comprises a moving device, which can drive the pipetting needle to move, so that the pipetting needle can draw waste liquid into the designated reaction tank.

6. The liquid transfer mechanism in a protein blotting instrument according to claim 5, characterized in that: The moving device includes a synchronous belt mechanism, which is driven by a second motor. The moving device also includes a second frame, which is slidably connected to the first frame, and the first frame is connected to the conveyor belt of the synchronous belt mechanism through a connecting device; The mobile device further includes a positioning sensor, which is mounted on the second frame and is used to monitor the real-time position of the first frame, thereby indirectly reflecting the real-time positions of the liquid discharge tube and the liquid aspiration needle. The second frame is provided with a protrusion, and the protrusion can limit the position of the first frame; When the liquid-pipetting needle extracts the waste liquid in the reaction tank, the reaction tank is in a horizontal position or tilted toward the position of the liquid-pipetting needle.

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